In the microwave art sometimes so called stripline circuits are used instead of wave guides to conduct microwave signals. Such circuits consist of thin tapes or strips of conducting material, etched on laminates of dielectric material. An applicable area is in producing microwave antennas, described, for example, in U.S. Pat. No. 4,150,383. Such an antenna consists of dielectric slabs with the antenna elements formed as stripline circuits.